Mating on Lucerne lands can reduce fertility
By Dr Mackie Hobson BSc(Agric),BVSc

Mating on Lucerne lands can reduce fertility

It is very rare that lucerne would affect performance; however, diseased stands of lucerne can reduce ovulation rates and result in poor reproductive performance in Angora goats (sheep and cattle). This has been observed on a farm in the karoo where Angora stud ewes were maintained and mated on lucerne lands.

Intake of pasture lucerne before mating can reduce ovulation rates by 20% by reducing the number of eggs shed per oestrus and reducing the proportion of eggs fertilised. The symptoms of estrogenism also include excessive mammary development and on rare occasions dystocia.

Oestrogenic hormones may be produced either by the lucerne (plant oestrogens or phytoestrogens) or by soil-borne fungi that live on the lucerne. The presence of leaf diseases, insect damage and severe moisture stress can all increase coumestans levels. Coumestan-induced infertility is generally considered as temporary.

Lucern hay has much lower levels of oestrogenic hormones and has not reportedly affected fertility.

The general advice is not to feed high risk Lucerne pasture to breeding Angora ewes in the 21 days prior to and during mating.

References:

Forage Plant Estrogens. A. L. Livingston, Journal of Toxicology and Environmental Health. 4: 301. 1978.

Toxicological Problems in Food Animals Affecting Reproduction. M. R. Putnam, Clinical Toxicology, In: Veterinary Clinics of North America: Food Animal Practice. 5: 325. 1989.

Detection of the Effects of Phytoestrogens on Sheep and Cattle. N. R. Adams, J. Animal Science. 73: 1509. 1995.